It’s the fall of 1981. Point Loma is playing La Jolla in the storied “Shoe” game.

A sea of fans, decked in red and black, feverishly cheer as the Vikings complete a simple out route.

First down.

From across the field, Eric Allen mentally photographs the moment. It’s embedded now.

“Why did they run that particular route in that particular situation,” the junior Pointers cornerback recalled thinking. “I took a mental note.”

On the next play, Allen chuckled. It looked eerily familiar.

“They switched the receiver to my side this time, inside the numbers again,” Allen said. “I’m thinking to myself, no, they’re not running the same route. They can’t do that. There’s no way that they would throw that same route the very next play.”

“I didn’t have to expend any great amount of energy. I didn’t have to perform this miraculous one-handed catch or anything. I just had to diagnose the play before the ball was snapped — a pre-snap read — and then follow my instincts. That’s when the light bulb went off.”

Allen never played the same again. He followed his instincts to Arizona State and then into the NFL like 180 plus other San Diegans.

San Diego has long been an NFL factory over the years, particularly at defensive back, where it has produced 44 league players — the most in any one area. Perhaps the greatest high school DB was Marcus Allen, who made his mark elsewhere in the pros.

The county has seen greats such as Eric Allen, John Lynch, Leon Hall, Bryant Westbrook and Jim Smith develop a penchant for lockdown coverage, hitting and aerial theft at the high school level before blossoming into NFL-caliber players.

Lincoln leads the category with six defensive backs.

“There is always a great respect and affinity because I think there is such a rich history of success in San Diego high school football,” Lynch said.

“Quarterbacks usually find other quarterbacks at the end of the game in the NFL or in college. Well, San Diego guys find San Diego guys. I think it’s a special brotherhood.”

None of San Diego’s defensive luminaries have had Eric Allen’s or Lynch’s impact in terms of productivity or longevity in the NFL.

Through 14 seasons in the league, stints with the Philadelphia Eagles, New Orleans Saints and Oakland Raiders, Allen produced 54 interceptions — 20th all-time — and eight touchdowns, earning six Pro Bowl and four All-Pro selections.

Origins of budding careers for Lynch and Allen trace back to the prep level. “Grassy back” — as they nicknamed Lynch — was a quarterback, linebacker and defensive back for the Falcons.

At Stanford, the legendary Bill Walsh converted Lynch permanently to safety, opening up the possibility for a career in the NFL. It paid off. The Tampa Bay Buccaneers drafted him in the third round in 1993 after Lynch turned down a contract as a starting pitcher with the Florida Marlins.

“I loved baseball, but I had a passion for football,” Lynch said. “I followed my heart, although many thought I was a better baseball player.”

Smart decision.

Under legendary Pointers coach Bennie Edens, the stars aligned for Allen. Edens introduced the X’s and O’s of football, which triggered Allen’s “life-altering football moment” against La Jolla.

It eventually birthed the nickname “Allstate” — derived from the insurance company — because Allen always kept Point Loma “in good hands.”

“When you receive an honor from your hometown such as this, it’s more meaningful than any other awards,” Allen said.

“All those people that helped you get there — my brother, my mom, my grandparents, school buddies, my wife — they get recognized, too. They are just as important a piece of you getting there as the light bulb going off against La Jolla.”